The purpose of this project is to develop an understanding of the role of specific neurotransmitters in basal ganglia function, with the goal of developing improved strategies for pharmacological treatment of neurological disorders. Topics currently under investigation include (1) the ways in which systemically administered dopamine agonists may affect neuronal activity in the pars reticulata and pars compacts of the substantial nigra and in the globus pallidus; (2) the ability of iontophoresed dopamine to modulate the actions of other neurotransmitters in these brain regions and (3) effects of GABA, GABA agonists, and drugs, such as the benzodiazepines which modulate GABA's effects on the activity of identified regions of the basal ganglia and substantia nigra.